1. Field of the Invention
It is well known that archery is an extremely difficult sport, in that the delivery of an arrow accurately to a target depends upon several variables. These variables include the length and position of the draw, the steadiness with which the bow is held in the hand and the release of the arrow from the same anchor point with each shot. In addition, the elevation of the arrow must be adjusted to compensate for the distance over which it is to travel and adjustments must frequently be made for windage. The delivery of an arrow accurately in order to kill game efficiently is particularly difficult because of these variables. This difficulty is increased because of the human error in accurately judging distance, a shortcoming which sometimes results in the arrow either falling short of, or flying over the target. Such errors in judging distances can be minimized by the use of sight pins and sighting devices of various design, which aid the archer in determining the distance to the target.
2. Description of the Prior Art
Various devices are known in the art for increasing the accuracy of an arrow delivered to a target. Typical of such devices is the "Archer's Bow" disclosed in U.S. Pat. No. 2,001,470, dated May 14, 1935, to Y. J. Nyvall, which device discloses a folding bow having a pair of top and bottom mirrors serving to reflect the target, the image of which is reflected by the top mirror to the eye of an archer. The lower mirror is reticulated in such relation to the longitudinal center of an arrow seated on arrow support ledges in the bow, that when the target appears in the lower mirror at the intersection of cross-hairs in the reticule, the arrow can be accurately directed toward the target. The patent makes it clear, however, that an aiming allowance must be made for trajectory and for air currents. U.S. Pat. No. 3,163,697, dated Dec. 29, 1964, to D. S. White, discloses an "Archery Bow Sight Utilizing Optical Range Finder and Coupled Sighting Element". The patent is drawn to a dual, spaced mirror device arranged such that the viewer will simultaneously see both a real and a reflected target image. As the viewer looks at the target, a slide is manipulated until real and reflected images are both seen at the same height. When this position is reached, the bow is aimed at the target and is properly positioned such that an arrow shot from the bow will assume the proper trajectory for the distance to the target. U.S. Pat. No. 3,524,440, dated Aug. 18, 1970, to Walter D. Hill, discloses an "Archery Bow Including Mirror Sighting Device" which includes an upper and lower mirror aligned in substantially vertical relationship with respect to each other forwardly of the bow, with cross-hairs or other target-aligning means mounted on one of the mirrors. The lower mirror is focused on the target, while the upper mirror is focused on the lower mirror and reflects the target image to the archers eye. The mirror mounting the cross-hairs may be adjusted vertically to compensate for distance, and horizontally, to compensate for windage. U.S. Pat. No. 3,861,051, dated Jan. 25, 1975, to Gerald I. Killian, discloses an "Arrow Draw Check for Archery Bows" which includes a mirror mounted for movement with an archery bow sight and arranged to reflect to the eye of the archer, the image of a tip of a drawn arrow in registry with an index mark on the mirror. A "Range Finding Device for Archery Bows" is disclosed in U.S. Pat. No. 2,788,701, dated Apr. 16, 1957, to G. G. Browning, which device incorporates multiple mirrors mounted below a single upper mirror for reflecting the image of the target and transmitting this image to the eye at various levels to facilitate trajectory adjustment of the bow for accurate delivery of an arrow to a target.
In my copending Application Ser. No. 512,355, filed July 11, 1983, I describe a bow sight which is characterized by a periscope device enclosing a top mirror and a bottom mirror mounted in generally 45.degree. angular relationship in order to transmit an image from the top to the bottom mirror. A compensating mirror is also mounted in the housing in generally parallel, but adjustable relationship with respect to the top and bottom mirrors and an opening in the housing allows the target image received by the compensating mirror to be reflected onto the bottom mirror, along with the image in the top mirror, such that a split target image is viewed in the fixed bottom mirror. Comparison of this split target image facilitates raising the bow to a proper angle in order to compensate for the drop of the arrow from the bow to the target.
It is an object of this invention to provide a bow sight for long bows, recurve bows and compound bows, which sight assists the archer in adjusting the bow trajectory for distance without the necessity of determining the distance between the viewer and the target.
It is a further object of this invention to provide a bow sight which is applicable to bows of varying contour, design and construction and which uses an adjustable compensating mirror in cooperation with an adjusting mechanism, a top mirror and a fixed bottom mirror to compensate for the drop of an arrow over a wide range of distances.
Another object of this invention is to provide a new and improved sighting device for long bows, recurve bows and compound bows, which sighting device is characterized by a housing carrying three enclosed mirrors in parallel relationship, one of which mirrors is adjustably mounted at the top of the housing, another fixedly mounted at the bottom of the housing and the third and more narrow compensating mirror pivotally located between the top and bottom mirrors and aligned with an opening in the housing, for adjustment by means of a lever to align the segments of a split target image projected in the bottom mirror from the top mirror and the compensating mirror, when a range compensation in elevation must be made relative to a straight line between the viewer and the target.
A still further object of the invention is to provide a new and improved bow sight for recurve bows, long bows and compound bows which includes a periscope device having an image-receiving compensating mirror adjustably mounted between parallel top and bottom mirrors, which compensating mirror is pivoted responsive to manipulation of a lever from a calibrated position to align corresponding image segments reflected in the bottom mirror by the compensating mirror and the top mirror and thereby determine the degree of elevation necessary to compensate for the drop of the arrow over the distance between the viewer and the target.